1. Field of the Invention
The present invention relates to a position indicating device for a circuit breaker, and particularly, to a position indicating device for a circuit breaker capable of fast and precisely indicating a position of the circuit breaker moved is within a cradle in which the circuit breaker is accommodated.
2. Background of the Invention
In general, a circuit breaker for high voltage is categorized into a pull-out type and a stationary type. The stationary type circuit breaker merely has a breaker main body secured at a position within an electric power distributing board. The pull-out type circuit breaker includes a movable carriage for conveying a breaker main body to facilitate maintenance and repair of the circuit breaker, terminals electrically connected to a power source side and a load side of a circuit and an outer case, called a cradle, having terminals electrically connected to the breaker main body, structure of which allows push-in and pull-out of the breaker main body.
Here, the pull-out type circuit breaker is employed in a distributing board, by which various electric devices, including the circuit breaker, all disposed therein, are managed so as to drive or control a power station, a substation and the like and to drive a motor. Also, the circuit breaker is accommodated in the cradle secured with the distributing board, and has a run position and a test position. At the run position, a power source side terminal and a load side terminal of the circuit breaker are connected to those of the cradle to thereby be connected to a power source and a load of a circuit so that the circuit breaker is operable, while at the test position, those terminals of the circuit breaker are separated from the terminals of the cradle so that a switching operation of the breaker main body is merely tested.
In order for an operator to move the breaker main body to the test position with respect to the cradle, first, an interlock link provided at the breaker main body is held up and the breaker main body is pulled out. The interlock link is then inserted in a test position determining groove of an interlock plate provided at the cradle. At the position, the power source side terminal and the load side terminal of the breaker main body are separated from those of the cradle. Accordingly, control power is merely supplied to the breaker main body, thereby merely allowing the switching test of the circuit breaker main body. Here, the operator can identify the corresponding position of the breaker main body by viewing a word, which is written on an indication sticker for indicating a test position, the indication sticker located on an upper surface of the interlock plate of the cradle.
Also, the operator may connect the terminals of the breaker main body to those of the crank so as to change the position of the circuit breaker from the test position to the run position at which the circuit is connected to the breaker main body. Here, the operator holds up the interlock link to separate the same from the test position determining groove and then pushes the breaker main body toward the cradle terminals, thereby moving the breaker main body. Afterwards, the interlock link is inserted into a run position determining groove of the cradle so that the breaker main body is located at the run position. After the breaker main body is moved to the run position, the operator can identify the corresponding position by viewing a word, which is written on an indication sticker for indicating the run position, the indication sticker also located on the upper surface of the interlock plate of the cradle.
Here, the circuit breaker, as aforementioned, includes the circuit breaker main body and the movable carriage. The circuit breaker main body includes a plurality of terminals connectable to a power source side terminal and a load side terminal of the cradle, respectively, a main circuit portion provided with contacts prepared for each AC phase, a vacuum interrupter and the like for breaking a circuit between a power source and a load upon occurrence of a fault current on the circuit, and a switching mechanism for switching by closing or opening the main circuit portion. The movable carriage is employed to move the circuit breaker main body to the run position or the test position.
In the configuration of the cradle and the circuit breaker according to the related art, the indication sticker for indicating a position (run or test position) of the breaker main body is attached onto the upper surface of the interlock plate, which is located at a bottom surface of the cradle and the operator identifies the position of the breaker main body by checking the indication sticker attached on the position after moving the breaker main body to the corresponding position. However, the position indication sticker is not easily viewed due to being obscured by the circuit breaker main body, which results in difficulty in the fast and precise recognition of the position of the circuit breaker main body.